Ultrasound (US) is a valuable tool for imaging musculoskeletal changes in osteoarthritis. It shows early and late findings related to inflammation and structural damage. Sonography is a safe tool, which has recently registered an increasing and widespread use, it being considered as a bedside procedure in the clinical assessment of rheumatic patients. Its applications in osteoarthritis are related to easy accessibility of equipment, low cost, short duration of single examinations and the possibility of performing a multiregional joint evaluation in the same scanning session. Permitting an extensive evaluation of most joint changes present in osteoarthritis, it gives the opportunity to monitor disease progression and perform a follow-up of the response to different local and systemic treatments. US-guided procedures are commonly performed with safety, reliability and optimal patient tolerance. Development in technology and technique with improvement of new research studies will further amplify the diagnostic role of ultrasound in osteoarthritis in the near future.